Peripheral field-of-view illumination system for a head mounted display

ABSTRACT

A display system for a head mounted device that illuminates the peripheral regions of the user&#39;s field of view to enhance an immersive experience. The system may use peripheral light emitters to the left and right of one or more central displays. Peripheral light emitters may provide lower resolution images, or only with vertical resolution, corresponding to the user&#39;s lower resolution vision in these peripheral regions. Reflective surfaces and lenses may be used to direct peripheral light into desired shapes and patterns. Rendering of peripheral light colors and intensities at each peripheral pixel may use approximations for improved performance since users may not be sensitive to precise color values in the peripheral regions.

This application is a continuation in part of U.S. Utility patentapplication Ser. No. 14/820,774, filed Aug. 7, 2015, the specificationof which is hereby incorporated herein by reference.

BACKGROUND OF THE INVENTION

Field of the Invention

One or more embodiments of the invention are related to the field ofvirtual reality systems. More particularly, but not by way oflimitation, one or more embodiments of the invention enable a headmounted display system that uses a peripheral field-of-view illuminationsystem to create an immersive image covering a significant portion of auser's natural field of view.

Description of the Related Art

Virtual reality systems are known in the art. Such systems generate avirtual world for a user that responds to the user's movements. Examplesinclude various types of virtual reality headsets and goggles worn by auser, as well as specialized rooms with multiple displays. Virtualreality systems typically include sensors that track a user's head,eyes, or other body parts, and that modify the virtual world accordingto the user's movements. The virtual world consists of athree-dimensional model, computer-generated or captured from real-worldscenes. Images of the three-dimensional model may be affected by theuser's position and orientation, or by other factors such as the user'sactions or parameters of the user's physical state. Generation of theseimages requires rendering of the three-dimensional model onto one ormore two-dimensional displays that are integrated into a head mounteddevice.

A major challenge for existing virtual reality systems is that they havelimited fields of view. These systems typically use head mounted deviceswith flat displays positioned in front of and parallel to the user'seyes. The field of view as seen by the user extends only to the edges ofthe display. The geometry and design of existing head mounted displaydevices provides a horizontal field typically on the order of 100degrees. This field of view is far below the user's natural horizontalfield of view, which is more than 180 degrees. Users therefore do notperceive the virtual reality environment as completely realistic.

In particular, existing virtual reality systems typically do not projectany images into the peripheral regions of the user's field of view.User's have relatively low resolution vision in these peripheralregions, but complete lack of images in the peripheral regionscompromises the quality of the virtual reality environment.

For at least the limitations described above there is a need for aperipheral field-of-view illumination system for a head mounted display.

BRIEF SUMMARY OF THE INVENTION

One or more embodiments described in the specification are related to aperipheral field-of-view illumination system for a head mounted display.

One or more embodiments of the system use a pair of angled displays anda lens system to create an immersive image covering a significantportion of a user's natural field of view. One or more embodiments usedisplays that are substantially flat; this configuration results in awide field-of-view image using a compact display device that useseconomical and readily available flat displays.

One or more embodiments of the system are incorporated into, attachedto, or embedded in a mount that is configured to be worn on the head ofa user or placed near the head of a user. This mount may include forexample, without limitation, glasses, smart glasses, sunglasses,goggles, virtual reality goggles, a helmet, a visor, a hat, binoculars,a monocular, a telescope, or a microscope.

One or more embodiments include a left display and a right display, eachlocated in front of the respective eye of the user. In one or moreembodiments, the left display and right display may be substantiallyflat. Use of flat or substantially flat displays may provide cost andsourcing advantages since flat displays are readily available and can bemanufactured at low cost. In one or more embodiments the left displayand right display may be curved or formed from multiple sections angledwith respect to one another; while curved displays may be more expensivein some cases, they may also simplify the geometry and optics of thesystem. Embodiments may use displays of any size or shape, along withone or more lenses to potentially increase the field of view.

In one or more embodiments, the left display and right display may beangled with respect to one another, rather than being parallel. Forexample, the angle between a plane tangent to the left display and aplane tangent to the right display may be less than 180 degrees, whenmeasured from the side near the eyes of the user. This configuration maybring the left edge of the left display closer to the user's left eye,increasing the horizontal field of view perceived by the user.Similarly, this configuration may bring the right edge of the rightdisplay closer to the user's right eye, increasing the horizontal fieldof view perceived by the user.

One or more embodiments may include one or more lenses between thedisplays and the user's eyes. These lenses may for example form imagesof the displays that extends across a wider field of view than thedisplays themselves without the lenses. The lens or lenses may thereforeincrease the apparent field of view of the system. In one or moreembodiments some or all of the pixels of the left and right displays maybe substantially in focus when viewed through the lens or lenses. In oneor more embodiment some or all of the pixels of the left and rightdisplays may be out of focus to create diffuse images in certainportions of the field of view, for example at the periphery.

Embodiments of the system may use any type, number, and configuration oflenses. In one or more embodiments, one or more of the lenses may be agradient index lens. A gradient index lens for example may providesignificant curvature of the light rays from the displays with arelatively thin lens. In one or more embodiments, one or more of thelenses may be a Fresnel lens, which may also provide significantcurvature of light rays with a relatively thin lens. One or moreembodiments may use one or more holographic optical elements inconjunction with or in place of one or more lenses.

The image formed by the lens or lenses may be of any size and shape, andmay extend across any vertical or horizontal field of view. In one ormore embodiments the horizontal field of view of the image may forexample exceed 120 degrees, 150 degrees, 180 degrees, or any otherdesired extent.

One or more embodiments of the system may use lower resolution at theperiphery than in the central region of the user's field of view, tocorrespond to the variable resolution of the user's vision across thefield of view. For example, one or more embodiments may include lightemitting elements to the left of the left display, or to the right ofthe right display. These peripheral light emitting elements may forexample be of lower resolution than the resolution of the left and rightdisplays. In one or more embodiments the peripheral light emittingelements may have for example only vertical resolution and little or nohorizontal resolution. In one or more embodiments the light from theperipheral light emitting elements may be directed by the lens or lensestowards the peripheries to form for example diffuse, low-resolutionlight in the peripheral portions of the user's field of view. In one ormore embodiments the peripheral light emitters may be portions of theleft and right displays, with pixels from these peripheral portionsdirected by the lens or lenses away from the focal points for thecentral regions of the left and right displays.

One or more embodiments of the system may use peripheral light emitterson the right and left sides of one or more central displays, either withor without lenses. The central displays may form one or more displayimages in a central portion of the user's field-of-view, and the lightfrom the peripheral light emitters may be projected to the sides of thedisplay images to fill all or a portion of the user's peripheralfield-of-view.

In one or more embodiments the combined field of view from the centraldisplay images and the light from peripheral light emitters may span theuser's entire natural field of view, which may exceed for example 180degrees. One or more embodiments may generate images and peripherallight that spans a portion of the user's field of view, such as forexample, without limitation, 120 degrees, 150 degrees, or 180 degrees.

Embodiments may use any number and configuration of peripheral lightemitters. For example, in one or more embodiments, the peripheral lightemitters may comprise a single left column of peripheral light pixels tothe left of the central displays, and a single right column ofperipheral light pixels to the right of the central displays. Thisarrangement provides only vertical resolution in the peripheral regionsof the user's field of view. Other embodiments may provide both verticaland horizontal resolution in the peripheral regions. Embodiments may useany desired resolution for both central displays and peripheral lightemitters, including for example resolutions of the peripheral lightemitters that are lower than the resolution of the central displays, tomatch the user's lower vision resolution in these regions. In one ormore embodiments, peripheral light emitters may be configured with anydesired peripheral light pixel pattern with any desired vertical andhorizontal resolution.

In one or more embodiments the light from peripheral light emitters maybe directed towards the peripheral areas of the user's field of view,either directly or using one or more lenses. In one or more embodiments,reflective surfaces may be used on the peripheral regions of theviewable area of the mount to direct light towards the user. These leftand right reflective surfaces may for example provide specular ordiffuse reflection to generate peripheral light of any desired patternand intensity. Reflective surfaces may be of any material, shape, size,color, and reflectivity. They may reflect all or any portion of thelight falling on the surfaces towards the eyes of the user.

One or more embodiments of the system may include one or more renderersthat generate the images viewed by the user from a 3D model of a scene.A 3D model may be for example a virtual reality environment, or videoscaptured of a real scene from several angles, or a combination ofcomputer-generated and real elements. One or more embodiments may use adisplay renderer to generate the pixels for one or more centraldisplays, and a peripheral renderer to determine the light colors andintensities for the peripheral light pixels of one or more peripherallight emitters. Because some embodiments may use peripheral lightemitters of relatively low resolution compared to the central displays,one or more embodiments may employ various peripheral renderingapproximations to calculate the light values for the peripheral lightpixels. While these approximations may be inappropriate in some casesfor the central display, where the user's field of view has highresolution, they may be sufficient for the peripheral field of view.Moreover, use of peripheral rendering approximations may reduce thecomputational and memory requirements for the system, potentiallylowering cost and improving display latency.

One or more embodiments may calculate a peripheral renderingapproximation that uses sample points within a peripheral light pixelarea, and casts a ray from the user's eye (the left eye for the leftperipheral light pixels, and the right eye for the right peripherallight pixels) through each sample point towards the 3D model. Usingraycasting techniques known in the art, the color of the sample pointmay be determined by selecting the color of the first object in the 3Dmodel hit by each ray. One or more embodiments may use for example anaverage of the sample point colors from raycasting to set the color forthe associated peripheral light pixel.

One or more embodiments may calculate a peripheral renderingapproximation that uses the pixel colors for central display pixelsadjacent to or near to each peripheral light pixel. For example, one ormore embodiments may use an average color for the adjacent or nearestdisplay pixels as the color for each peripheral light pixel. Thisapproximation may be highly efficient since the rendering performed bythe display renderer is used directly for the peripheral rendering.

One or more lenses may be used in conjunction with any of theembodiments described above. Any type, number, and configuration oflenses may be used. Lenses may be for example, without limitation,gradient index lenses, Fresnel lenses, or traditional convex or concavelenses of uniform material.

BRIEF DESCRIPTION OF THE DRAWINGS

The patent or application file contains at least one drawing executed incolor. Copies of this patent or patent application publication withcolor drawing(s) will be provided by the Office upon request and paymentof the necessary fee.

The above and other aspects, features and advantages of the inventionwill be more apparent from the following more particular descriptionthereof, presented in conjunction with the following drawings wherein:

FIG. 1 illustrates the typical field of view of a user, and thechallenge of creating a wide field-of-view display for a head mountedsystem.

FIG. 2 illustrates the geometry of an embodiment of the system that hasflat left and right displays at an angle, and a lens between thedisplays and the users' eyes that enlarges the field of view.

FIG. 3 illustrates an embodiment of head mounted system thatincorporates a wide field-of-view display.

FIG. 4 shows a three dimensional model of the displays and lens for anembodiment of the system.

FIG. 5 shows a cross sectional view of the embodiment shown in FIG. 4,illustrating how the lens bends light rays emitted from the displays.

FIG. 6 illustrates the high resolution central field of view of a user,and the relatively low resolution peripheral field of view of the user.

FIG. 7 illustrates an embodiment of the system that provides a highresolution display for the central portion of a user's field of view,and low resolution display for the peripheral portion of the user'sfield of view.

FIG. 8 illustrates an image as viewed for example in an embodiment ofthe system as illustrated in FIG. 7.

FIG. 9 illustrates an embodiment of the system that provides potentiallylower resolution diffuse light for the peripheral vision regions of theuser's field of view, using a lens to project unfocussed light towardsthe periphery.

FIG. 10 illustrates an embodiment of the system that has a centraldisplay and a series of low-resolution, vertically spaced peripherallight pixels to the left and right of the central display.

FIG. 11 illustrates a variation of the embodiment shown in FIG. 10, withmultiple vertical columns of peripheral light pixels on either side ofthe central display.

FIG. 12 illustrates a variation of the embodiment shown in FIG. 10, withperipheral light pixels positioned at the outer edges of the viewablearea of the mount.

FIG. 13 illustrates a variation of the embodiment shown in FIG. 10, witha left and right low-resolution display on the sides of the higherresolution central display.

FIG. 14 illustrates an embodiment of the system with reflective left andright edges that reflect light from the peripheral light emitterstowards the user's eyes.

FIG. 15 illustrates an embodiment of the system that includes a displayrenderer to render display pixels from a 3D scene, and a peripheralrenderer to render peripheral light pixels from the 3D scene.

FIG. 16 illustrates an embodiment of a peripheral renderer that sets aperipheral light pixel color by sampling points within an areaassociated with the pixel, and averaging the color of the sampledpoints.

FIG. 17 illustrates an embodiment of a peripheral renderer that sets aperipheral light pixel color by averaging the colors of the adjacentpixels in a central display.

DETAILED DESCRIPTION OF THE INVENTION

A peripheral field-of-view illumination system for a head mounteddisplay will now be described. In the following exemplary descriptionnumerous specific details are set forth in order to provide a morethorough understanding of embodiments of the invention. It will beapparent, however, to an artisan of ordinary skill that the presentinvention may be practiced without incorporating all aspects of thespecific details described herein. In other instances, specificfeatures, quantities, or measurements well known to those of ordinaryskill in the art have not been described in detail so as not to obscurethe invention. Readers should note that although examples of theinvention are set forth herein, the claims, and the full scope of anyequivalents, are what define the metes and bounds of the invention.

FIG. 1 illustrates the challenge of providing a wide field-of-viewdisplay for a head mounted device. A typical user has a horizontal fieldof view 101 for the left eye and 102 for the right eye that each spanapproximately 155°. The combined field of view 103 for both eyes spansapproximately 190°. In contrast, a typical head-mounted display like 110has a small horizontal field of view 111. Thus a user with a typicalhead-mounted display like 110 does not have an immersive experiencesince much of the user's natural field of view is unused. FIG. 1illustrates two potential approaches to enlarging the field of view ofthe display. One option is to use a much larger display 112, whichincrease the horizontal field of view to 113. This approach isundesirable because it results in displays that are bulky, heavy, andexpensive. Another theoretical approach is to curve the display aroundeach eye, as shown in 120. A disadvantage of this approach is thatcurved displays surrounding the entire field of view around an eye arenot readily available and they may be expensive to manufacture.

FIG. 2 illustrates an approach used in one or more embodiments of theinvention to increase the field of view of the display beyond that of atypical device 110 in FIG. 1. The display is separated into a leftdisplay 201 in front of the left eye of the user, and right display 202in front of the right eye of the user. In the embodiment shown in FIG. 1the left and right displays are flat or substantially flat, which may insome cases provide cost or sourcing advantages. In one or moreembodiments the left or right display (or both) may be further segmentedinto multiple displays. In FIG. 2, the left edge of display 201 isangled towards the user 100, which brings this left edge further towardsthe leftward extreme of the user's field of view. Similarly the rightedge of display 202 is angled towards the user, which brings the rightedge further towards the rightward extreme of the user's field of view.The left display 201 and right display 202 are therefore not parallel;they are at an angle 203 that is less than 180°. The left eye field ofview 204 that results from angling the display may be larger in someembodiments that the corresponding field of view for a narrow angle flatdisplay like display 101 in FIG. 1. Embodiments may use left and rightdisplays of any size and shape. In one or more embodiments the left andright displays may be curved for example, or formed from multiplesections lying on different planes, instead of flat as shown in theembodiment of FIG. 1. One or more embodiments may use flat displays forease of manufacturing and sourcing. The angles 203 and 204 are onlyillustrative; one or more embodiments may use any angle between left andright displays, and may use any desired width and height for the leftand right displays. For embodiments that use curved displays, the anglebetween displays may be considered for example to be the angle betweenplanes that are tangent to each display at selected points on thedisplays.

One or more embodiments may further extend or alter the field of viewfor the display by using one or more lenses between the displays and theeyes of the user. This is illustrated in the right side of FIG. 2, withlens 210 between the displays and the user's eyes. One or moreembodiments may use any number and configuration of lenses to bend,focus, or otherwise direct the light emitted or reflected from thedisplays. Lenses may be of any desired material and shape. One or moreembodiments may use one or more adjustable lenses that may for examplebe focused or otherwise adjusted by a user. In FIG. 2, Lens 210 bendsthe light rays emitted from the displays 201 and 201 so that they appearto be coming from different directions. Thus the image of the displaypixels viewed by the user may have a larger field of view than thedisplays themselves (without the lens or lenses). For example, light ray212 from pixel 211 on left display 201 is bent by lens 210, so that theapparent direction 213 of this pixel is further to the right than thedirection 205 of the pixel when viewed without the lens. Thus thehorizontal field of view 214 of the image of the left display with thelens is greater than the field of view 204 without the lens. Similarlythe field of view of the image of the right display with the lens isgreater than the field of view without the lens. One or more embodimentsmay therefore use one or more lenses to enlarge the apparent field ofview of the displays.

FIG. 3 illustrates an embodiment that incorporates a wide field of viewdisplay into mount 301. Axis 311 (z) of the figure as shown pointsbackwards (into the user's eyes); axis 313 (x) points left-to-right, andaxis 312 (y) points bottom-to-top. The front area 302 of the mounthouses for example the left and right displays and the lens or lenses(for example as shown in FIG. 2). Speaker 303 may be used in one or moreembodiments to provide audio in addition to video. The shape andcomponents illustrated in FIG. 3 are illustrative only; embodiments mayincorporate a wide field of view display system into any head mounteddevice of any size, shape, and configuration.

FIG. 4 illustrates several 3D views of an embodiment of the system fromdifferent orientations. Only the displays and lens are shown; otherelements of a mount (such as for example the mount of FIG. 3) are notshown. The coordinate axes from FIG. 3 are shown for reference for eachview. In the back left view, cutout 401 in the lens 210 is apparent;this cutout is for the user's nose. One or more embodiments may uselenses or displays of any shape or size. For example, lenses or displaysmay be configured to conform to any shape of a user, or of any deviceworn by or used by a user. As an example, one or more embodiments may beconfigured to be attached to any device worn by a user, such as forexample, without limitation, glasses, sunglasses, goggles, helmets,visors, hats, contact lenses, or ocular implants.

FIG. 5 shows a top view of an embodiment of the displays 201 and 202,and the lens 210. In this embodiment the lens is a gradient index lens,where the index of refraction of the lens changes continuouslythroughout the lens volume. One or more embodiments may use gradientindex optics for one or more of the lenses of the system. An advantageof gradient index optics is that light rays can be bent significantlyand in highly versatile ways using a relatively thin lens. For example,light can be focused in the middle area of a gradient index lens, butdeflected outward at the edges of the lens to fill the user's peripheralfield of vision. The gradient index lens entry and exit zones (layers)may also act as a collimator and optical relay to reduce the effect ofnon-parallel rays which would degrade the image. One or more embodimentsmay use Fresnel lenses. Fresnel lenses also provide the advantage ofbeing relatively thin. Embodiments may use any type of lens or lensesbetween the displays and the user's eyes. One or more embodiments mayuse combinations of different types of lenses. One or more embodimentsmay use one or more holographic optical elements to diffract, reflect,or transmit light in any desired pattern. Holographic optical elementsmay be used for example in conjunction with other lenses, or in place ofcertain lenses.

In a simple lens consisting of uniform material, refraction of lightrays occurs only at the lens surfaces. In a gradient index lens, such asthe lens 210 in FIG. 5, refraction may occur throughout the lens due tocontinuous variations in the index of refraction of the lens material.For example, light ray 501 bends throughout the lens material 210, andnot just at the boundaries of the lens. One or more embodiments may useany lens or combination of lenses to bend light in any desired manner,in order to form images of any shape and size. In the embodiment of FIG.5, lens 210 focus the light rays from left display 201 onto point 502,which may for example be at or near the left eye of the user, and itfocuses the light rays from right display 202 onto point 503, which mayfor example be at or near the right eye of the user.

One or more embodiments may optimize or otherwise configure the displayand lens system to reflect the variable resolution of human vision indifferent portions of the field of view. FIG. 6 illustrates thisvariable resolution. Human vision has relatively high resolution in thecentral region 601 of the field of view, and relatively poor resolutionin the peripheral regions 602 and 603. High resolution display or imagesin the peripheral regions of the field of view may therefore add littleor nothing to the user's experience. However, for an immersiveexperience, it is preferable to provide some image across the user'sentire field of view.

FIG. 7 illustrates a conceptual approach employed by one or moreembodiments to optimize the display system to reflect the variableresolution across the field of view. In the central region of the fieldof view, a high resolution display 701 is provided. In the peripheralleft and right regions of the field of view, low resolution displays 702and 703 are provided. In the embodiment illustrated in FIG. 7, theperipheral displays have only vertical resolution and they arehorizontally uniform. One or more embodiments may use peripheraldisplays with horizontal resolution as well as or instead of verticalresolution. Embodiments may use any desired density for central andperipheral displays. The technologies used to generate displays orimages for the central region may be different from those used for theperipheral regions in one or more embodiments. For example, anembodiment may use a standard rectangular pixel display for the centralregion, and use LEDs or other light emitting devices at a low resolutionfor the peripheral regions. The light emitting devices for peripheralregions may for example project coarse or diffuse light towards theperipheral areas of the viewing device. The intensity and color of thediffuse light in the peripheral regions may be determined for examplebased on average luminance or color values in peripheral regions of thescene being displayed.

FIG. 8 illustrates an image that may be produced by one or moreembodiments that uses low resolution images in the peripheral regions.In this illustrative example, the central area 701 of the image hassignificant vertical and horizontal resolution. The left and rightperipheral regions of the image 702 and 703 in this example have nohorizontal resolution, and relatively low vertical resolution.

One or more embodiments may use a lens or combination of lenses todirect the peripheral light or peripheral images towards the edges ofthe viewing device. FIG. 9 illustrates an embodiment that extends theexample shown in FIG. 5 to generate unfocused images in the periphery ofthe user's field of view. This embodiment has a left peripheral displayregion 901 to the left of display 201, and a right peripheral displayregion 902 to the right of display 202. In one or more embodiments aperipheral display region may be part of an integrated display thatincludes for example both 201 and 901. In one or more embodiments theperipheral display regions may instead be separate devices, such as forexample lower resolution displays or arrays of individual light emittingdevices. The lens 210, which may for example be a gradient index lens,bends the light from the peripheral display regions outward towards theedges of the viewing device. These light rays may for example notconverge at the focal points 502 and 503. For example, light ray 903from left peripheral display region 901 is bent outward by lens 210 andit does not converge on focal point 502. The user may therefore view theimages from regions 901 and 902 as diffuse, unfocused light rather thanas focused high resolution pixels.

One or more embodiments of the system may use peripheral light emitterswith or without lenses. FIG. 10 illustrates an embodiment of the systemfront viewable area 1001 positioned in front of the eyes of a user. Thisarea includes a high resolution central display 701, and two columns ofperipheral light pixels to the left and right of the central display.Each peripheral light pixel directs light towards the periphery of theuser's field of view. For example, right peripheral light pixel 1002directs light 1004 towards the right of the user's field of view, andleft peripheral light pixel 1003 directs light 1005 towards the left ofthe user's field of view. Embodiments may use any number, size,configuration, location, technology, and density of peripheral lightpixels. Embodiments may also use any number, size, configuration,location, technology, and density of central displays. Because of thedifferences in resolution between a user's central field of view andperipheral field of view, as illustrated for example in FIG. 6, one ormore embodiments may use relatively lower density of peripheral lightpixels compared to the density of pixels in the central display ordisplays. One or more embodiments may use peripheral light pixels thatemit diffuse light.

The configuration of peripheral light pixels shown in FIG. 10 isillustrative; FIGS. 11, 12, and 13 show some exemplary variations onthis configuration that may be used in one or more embodiments. In FIG.11 there are two columns of peripheral light pixels on each side of thecentral display 701—such as pixels 1002 and 1102 on the right and pixels1003 and 1103 on the left. This configuration provides a very coarsehorizontal resolution on the periphery, with a higher verticalresolution which is still below the vertical resolution of the centraldisplay 701. In FIG. 12 the peripheral light pixels are positioned atthe outer edges of the viewable area 1101, such as right peripherallight pixel 1202 and left peripheral light pixel 1203. These peripherallight pixels may for example direct light inward rather than outward. InFIG. 13 low-resolution rectangular displays 1301 and 1302 are used forperipheral light emitters. These peripheral displays may for example befor example LCD screens, OLED screens, or any other display technology.These configurations shown in FIGS. 10, 11, 12, and 13 are illustrative;embodiments may configure peripheral light emitters and their peripherallight pixels in any desired configuration or pattern.

FIG. 14 illustrates an embodiment of the system with a single centraldisplay 701, a left reflective surface 1401, and a right reflectivesurface 1402. These reflective surfaces may for example provide specularor diffuse reflection to generate peripheral light of any desiredpattern and intensity. An illustrative light ray 1403 is emitted by aperipheral light pixel, and it reflects off the surface towards theuser's right eye. In addition, one or more secondary rays such as 1404may be reflected in other directions, and some of these secondary raysmay also be reflected eventually back towards the eye of the user. Theeffect of these multiple reflections may be to create a diffuse patternof light that fills all or a significant portion of the user'speripheral field of view.

FIG. 15 illustrates an embodiment of the system that uses a displayrenderer 1502 and a peripheral renderer 1503 to generate central imagesand peripheral light from 3D model 1501 of a scene. In this example thedisplay renderer 1502 generates a relatively high resolution image forthe central display 701, and the peripheral renderer uses anapproximation to generate a low resolution image for the left peripherallight pixels 1504 and the right peripheral light pixels 1505.

One or more embodiments may use any desired approximations forperipheral rendering. Two illustrative approximations are shown in FIG.16 and FIG. 17. FIG. 16 illustrates an embodiment that determines thecolor of each peripheral light pixel by raycasting through a set ofsample points located within an area associated with the peripherallight pixel, and then averaging the colors obtained on each cast ray. Inthis example two sample points 1602 and 1603 are selected in peripherallight pixel area 1601. The area used for sampling points may for examplecorrespond to the physical size of the peripheral light pixel, or it mayfor example correspond to a region illuminated by this peripheral lightpixel (or to a portion of this region). Embodiments may associate anydesired area with each peripheral light pixel in order to determine thecolor of the peripheral light pixel. Embodiments may use any number ofsample points within each peripheral light pixel area; two sample pointsare shown here for illustration. Ray 1612 is drawn from the user's righteye through sample point 1602; the first object in 3D model 1501intersected by this ray determines the color selected for this samplepoint, which in this case is black. Similarly ray 1613 is drawn from theuser's right eye through sample point 1603, determining a blue color.These two colors are averaged to form color 1620, a dark blue, for thisperipheral light pixel. One or more embodiments may combine sampledcolors in any desired manner, including for example, without limitation,simple averaging, weighted averaging, maximizing, minimizing, randomselection, or any other procedure.

FIG. 17 illustrates another approximation technique that may be used forperipheral rendering in one or more embodiments. In this example, thecolor of each peripheral light pixel is determined based on the colorsof display pixels that are adjacent to or close to the peripheral lightpixel. This approximation may be very efficient since the displayrenderer has already calculated the pixel colors for the display ordisplays. Thus very little additional calculation is needed in thisexample to determine the color of each peripheral light pixel. In FIG.17, peripheral light pixel 1601 is adjacent to the three display pixels1701, which have colors red, white, and blue. The embodiment shown inFIG. 17 takes an average color value 1702 from the adjacent displaypixels and assigns this color value to the peripheral light pixel 1601.One or more embodiments may combine colors from display pixels in anydesired manner, including for example, without limitation, simpleaveraging, weighted averaging, maximizing, minimizing, random selection,or any other procedure.

The examples of peripheral rendering approximations shown in FIGS. 16and 17 are illustrative; any technique for generating the color ofperipheral light pixels from the 3D model of a scene is in keeping withthe spirit of the invention.

While the invention herein disclosed has been described by means ofspecific embodiments and applications thereof, numerous modificationsand variations could be made thereto by those skilled in the art withoutdeparting from the scope of the invention set forth in the claims.

What is claimed is:
 1. A peripheral field-of-view illumination systemfor a head-mounted display comprising: a mount configured to be worn ona head of a user; one or more displays coupled to said mount and locatedin front of a left eye and a right eye of said user; a left peripherallight emitter located on a left side of said one or more displays; aright peripheral light emitter located on a right side of said one ormore displays; a 3D model of a scene; a display renderer coupled to said3D model of said scene and to said one or more displays; and, aperipheral renderer coupled to said 3D model of said scene, to said leftperipheral light emitter, and to said right peripheral light emitter;wherein said one or more displays form one or more display images in acentral portion of said user's field-of-view; light from said leftperipheral light emitter is projected left of said one or more displayimages; light from said right peripheral light emitter is projectedright of said one or more display images; said left peripheral lightemitter and said right peripheral light emitter each comprise aplurality of peripheral light pixels located at different verticalpositions; said display renderer assigns a display pixel color to eachpixel of said one or more displays based on said 3D model of said scene;and, said peripheral renderer assigns a peripheral light pixel color toeach of said peripheral light pixels based on said 3D model of saidscene.
 2. The system of claim 1, wherein a total horizontalfield-of-view spanned by said one or more display images, said lightfrom said left peripheral light emitter viewed by said user, and saidlight from said right peripheral light emitter viewed by said user is atleast 120 degrees.
 3. The system of claim 1, wherein a total horizontalfield-of-view spanned by said one or more display images, said lightfrom said left peripheral light emitter viewed by said user, and saidlight from said right peripheral light emitter viewed by said user is atleast 150 degrees.
 4. The system of claim 1, wherein a total horizontalfield-of-view spanned by said one or more display images, said lightfrom said left peripheral light emitter viewed by said user, and saidlight from said right peripheral light emitter viewed by said user is atleast 180 degrees.
 5. The system of claim 1, wherein a total horizontalfield-of-view spanned by said one or more display images, said lightfrom said left peripheral light emitter viewed by said user, and saidlight from said right peripheral light emitter viewed by said user ismore than 180 degrees.
 6. (canceled)
 7. The system of claim 1, wherein avertical resolution of said peripheral light pixels is less than avertical resolution of each of said one or more displays.
 8. The systemof claim 1, further comprising one or more left reflective surfaceslocated to the left of said one or more displays; and, one or more rightreflective surfaces located to the right of said one or more displays;wherein at least a portion of said light from said left peripheral lightemitter is reflected from said one or more left reflective surfacestowards said left eye of said user; and, at least a portion of saidlight from said right peripheral light emitter is reflected from saidone or more right reflective surfaces towards said right eye of saiduser.
 9. (canceled)
 10. The system of claim 1, wherein said peripheralrenderer determines a peripheral light pixel area for each of saidperipheral light pixels; calculates a sample color for one or moresample locations within each of said peripheral light pixel areas to theleft of said one or more displays, from a color of a closest object insaid 3D model of said scene on a ray between said left eye of said userand said sample location; calculates said sample color for one or moresample locations within each of said peripheral light pixel areas to theright of said one or more displays, from a color of a closest object insaid 3D model of said scene on a ray between said right eye of said userand said sample location; averages the sample colors for all of saidsample locations within each of said peripheral light pixel areas toform an average color value for said peripheral light pixel area; and,assigns said average color value as the peripheral light pixel color forthe peripheral light pixel corresponding to each peripheral light pixelarea.
 11. The system of claim 1, wherein said peripheral rendereraverages said display pixel colors for pixels of said one more displaysthat are adjacent to or near to each of said peripheral light pixels, toform an average color value for each of said peripheral light pixels;and, assigns said average color value as the peripheral light pixelcolor for each of said peripheral light pixels.
 12. The system of claim1, further comprising one or more lenses coupled to said mount, eachlocated between one or more of the left and right eyes of said user andone or more of said one or more displays, said left peripheral lightemitter, and said right peripheral light emitter; wherein said one ormore lenses bend light from said left peripheral light emitter left;and, said one or more lenses bend light from said right peripheral lightemitter right.
 13. The system of claim 12 wherein at least one of saidone or more lenses comprise a gradient index lens.
 14. The system ofclaim 12 wherein at least one of said one or more lenses comprise aFresnel lens.
 15. The system of claim 12 wherein at least one of saidone or more lenses comprise a holographic optical element.
 16. Aperipheral field-of-view illumination system for a head-mounted displaycomprising a mount configured to be worn on a head of a user; one ormore displays coupled to said mount and located in front of a left eyeand a right eye of said user; a left peripheral light emitter located ona left side of said one or more displays; a right peripheral lightemitter located on a right side of said one or more displays; one ormore left reflective surfaces located to the left of said one or moredisplays; one or more right reflective surfaces located to the right ofsaid one or more displays; one or more lenses coupled to said mount,each located between one or more of the left and right eyes of said userand one or more of said one or more displays, said left peripheral lightemitter, and said right peripheral light emitter; a 3D model of a scene;a display renderer coupled to said 3D model of said scene and to saidone or more displays; and, a peripheral renderer coupled to said 3Dmodel of said scene, to said left peripheral light emitter, and to saidright peripheral light emitter; wherein said one or more displays formone or more display images in a central portion of said user'sfield-of-view; light from said left peripheral light emitter isprojected left of said one or more display images; light from said rightperipheral light emitter is projected right of said one or more displayimages; said left peripheral light emitter and said right peripherallight emitter each comprise a plurality of peripheral light pixelslocated at different vertical positions; a vertical resolution of saidperipheral light pixels is less than the vertical resolution of each ofsaid one or more displays; said one or more lenses bend light from saidleft peripheral light emitter left; said one or more lenses bend lightfrom said right peripheral light emitter right; at least one of said oneor more lenses comprise a gradient index lens or a Fresnel lens or aholographic optical element; a total horizontal field-of-view spanned bysaid one or more display images, said light from said left peripherallight emitter viewed by said user, and said light from said rightperipheral light emitter viewed by said user is at least 180 degrees; atleast a portion of said light from said left peripheral light emitter isreflected from said one or more left reflective surfaces towards saidleft eye of said user; at least a portion of said light from said rightperipheral light emitter is reflected from said one or more rightreflective surfaces towards said right eye of said user; said displayrenderer assigns a display pixel color to each pixel of said one or moredisplays based on said 3D model of said scene; and, said peripheralrenderer assigns a peripheral light pixel color to each of saidperipheral light pixels based on said 3D model of said scene.